How to install linux on a laptop?
Basically you should choose one of many linux distributions images available...
Basically you should choose one of many linux distributions images available from internet, burn a DVD or create a bootable pendrive from choosen image using unetbootin (or alternatives). If you need a recomendation I could sugest Linux Mint Cinnamon Edition for Windows coming people, and Ubuntu for those coming from MAC world, there are many others but I just tried these two so far. Boot form pendrive or DVD, try it without installing or install from there as you wish. If you already have installed an OS before would be relativelly easy.